hi all: When I porting my platform ehci driver on kernel v4.1, I get back trace like below without plug in any device and just insert usb-common.ko, usbcore.ko and ehci-hcd.ko. (and detail is show in the attachment) It seems caused by the PM related thread that is wakened up, even there is no device plug in and step in null pointer. Is there any callback function or flag in ehci-platform.c that we should check that will trigger the related PM work thread? Appreciate your kind help in advance, Backtrace: [<bf04ebec>] (ehci_handle_start_intr_unlinks [ehci_hcd]) from [<bf04ffb0>] (ehci_bus_suspend+0x388/0x464 [ehci_hcd]) r6:ede8152c r5:ede81480 r4:ede81300 r3:ede81550 [<bf04fc28>] (ehci_bus_suspend [ehci_hcd]) from [<bf00f2c8>] (hcd_bus_suspend+0xd0/0x1dc [usbcore]) r10:00000400 r9:edd8e940 r8:00000001 r7:bf024928 r6:00000007 r5:ede82f80 r4:ede81300 [<bf00f1f8>] (hcd_bus_suspend [usbcore]) from [<bf01ba0c>] (generic_suspend+0x24/0x44 [usbcore]) r8:00000402 r7:00000001 r6:00000007 r5:ffffffff r4:ede82f80 [<bf01b9e8>] (generic_suspend [usbcore]) from [<bf013730>] (usb_suspend_both+0x108/0x1a8 [usbcore]) [<bf013628>] (usb_suspend_both [usbcore]) from [<bf0145fc>] (usb_runtime_suspend+0x38/0x78 [usbcore]) r10:00000003 r9:00000008 r8:00000000 r7:60000113 r6:ede82f80 r5:ede82fe8 r4:00000000 r3:00000001 [<bf0145c4>] (usb_runtime_suspend [usbcore]) from [<c02c3e98>] (__rpm_callback+0x44/0x6c) r6:bf0145c4 r5:ede82fe8 r4:ede83058 r3:00000000 [<c02c3e54>] (__rpm_callback) from [<c02c3f38>] (rpm_callback+0x78/0x90) r6:00000000 r5:00000008 r4:ede82fe8 r3:00000004 [<c02c3ec0>] (rpm_callback) from [<c02c4560>] (rpm_suspend+0x28c/0x4a8) r5:00000008 r4:ede82fe8 [<c02c42d4>] (rpm_suspend) from [<c02c559c>] (__pm_runtime_suspend+0x40/0x8c) r10:00000000 r9:00000000 r8:eedd7400 r7:60000113 r6:00000008 r5:ede83058 r4:ede82fe8 [<c02c555c>] (__pm_runtime_suspend) from [<bf014694>] (usb_runtime_idle+0x34/0x3c [usbcore]) r7:00000002 r6:bf014660 r5:ede82fe8 r4:ede82fe8 [<bf014660>] (usb_runtime_idle [usbcore]) from [<c02c3e98>] (__rpm_callback+0x44/0x6c) r4:ede83058 r3:00000000 [<c02c3e54>] (__rpm_callback) from [<c02c4974>] (rpm_idle+0x148/0x2ec) r6:eedd3240 r5:00000000 r4:ede82fe8 r3:bf01d80c [<c02c482c>] (rpm_idle) from [<c02c56d4>] (pm_runtime_work+0x70/0x9c) r8:eedd7400 r7:c06e6100 r6:eedd3240 r5:ede83058 r4:ede830b4 r3:00000000 [<c02c5664>] (pm_runtime_work) from [<c003be98>] (process_one_work+0x250/0x428) r5:ede830b4 r4:ee0aa500 [<c003bc48>] (process_one_work) from [<c003c95c>] (worker_thread+0x2d0/0x424) r10:00000000 r9:ee0aa518 r8:eedd3260 r7:c06e6100 r6:eedd3240 r5:eedd3240 r4:ee0aa500 [<c003c68c>] (worker_thread) from [<c00412b0>] (kthread+0xf8/0x10c) r10:00000000 r9:00000000 r8:00000000 r7:c003c68c r6:ee0aa500 r5:00000000 r4:ee0bcc00 [<c00411b8>] (kthread) from [<c000fcd8>] (ret_from_fork+0x14/0x3c) r7:00000000 r6:00000000 r5:c00411b8 r4:ee0bcc00 Code: e5930028 e5942114 e1500002 0a000008 (e8930005)
bus: 'usb': registered bus: 'usb': add driver usbfs usbcore: registered new interface driver usbfs bus: 'usb': add driver hub usbcore: registered new interface driver hub bus: 'usb': add driver usb usbcore: registered new device driver usb ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver bus: 'platform': add driver Platform-ehci bus: 'platform': driver_probe_device: matched device fc1f0000.ehci with driver Platform-ehci bus: 'platform': really_probe: probing driver Platform-ehci with device fc1f0000.ehci [USB] 2015-04-16v00002 pdev : fc1f0000.ehci Platform-ehci fc1f0000.ehci: Platform EHCI Platform-ehci fc1f0000.ehci: new USB bus registered, assigned bus number 1 Platform-ehci fc1f0000.ehci: irq 10, io mem 0xfc1f0000 mapped f023e000 Platform-ehci fc1f0000.ehci: USB 2.0 started, EHCI 1.00, overcurrent ignored usb usb1: New USB device found, idVendor=1d6b, idProduct=0002 usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1 usb usb1: Product: Platform EHCI usb usb1: Manufacturer: Linux 4.1.10+ ehci_hcd usb usb1: SerialNumber: Platform device: 'usb1': device_add bus: 'usb': add device usb1 PM: Adding info for usb:usb1 bus: 'usb': driver_probe_device: matched device usb1 with driver usb bus: 'usb': really_probe: probing driver usb with device usb1 device: '1-0:1.0': device_add bus: 'usb': add device 1-0:1.0 PM: Adding info for usb:1-0:1.0 bus: 'usb': driver_probe_device: matched device 1-0:1.0 with driver hub bus: 'usb': really_probe: probing driver hub with device 1-0:1.0 hub 1-0:1.0: USB hub found hub 1-0:1.0: 1 port detected device: 'usb1-port1': device_add PM: Adding info for No Bus:usb1-port1 driver: 'hub': driver_bound: bound to device '1-0:1.0' bus: 'usb': really_probe: bound device 1-0:1.0 to driver hub device: 'ep_81': device_add PM: Adding info for No Bus:ep_81 driver: 'usb': driver_bound: bound to device 'usb1' bus: 'usb': really_probe: bound device usb1 to driver usb device: 'ep_00': device_add PM: Adding info for No Bus:ep_00 driver: 'Platform-ehci': driver_bound: bound to device 'fc1f0000.ehci' bus: 'platform': really_probe: bound device fc1f0000.ehci to driver Platform-ehci bus: 'usb': add driver usb-storage usbcore: registered new interface driver usb-storage Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 ================================================================================ SMP Send Stop Other CPU! ================================================================================ CPU1: stopping Process swapper/1 (pid: 0, stack limit = 0xee934210) CPU: 1 PID: 0 Comm: swapper/1 Tainted: G O 4.1.10+ #4 Hardware name: Platform-Cortex A9 task: ee905a00 ti: ee934000 task.ti: ee934000 PC is at arch_cpu_idle+0x40/0x4c LR is at arch_cpu_idle+0x3c/0x4c pc : [<c00107f8>] lr : [<c00107f4>] psr: 60000113 sp : ee935fb0 ip : ee935fb0 fp : ee935fbc r10: c06ea5a0 r9 : c06ea5a0 r8 : c04b7e2c r7 : ee935fc0 r6 : c06ce344 r5 : 00000015 r4 : ee934000 r3 : c06eace8 r2 : 00000000 r1 : 00000000 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 3df2404a DAC: 00000015 CPU: 1 PID: 0 Comm: swapper/1 Tainted: G O 4.1.10+ #4 Hardware name: Platform-Cortex A9 Backtrace: [<c0013954>] (dump_backtrace) from [<c0013bb8>] (show_stack+0x20/0x24) r6:00000000 r5:00000001 r4:00000000 r3:00200040 [<c0013b98>] (show_stack) from [<c04aea1c>] (dump_stack+0x7c/0xc8) [<c04ae9a0>] (dump_stack) from [<c00161d4>] (handle_IPI+0x190/0x2dc) r4:ee934210 r3:ee934000 [<c0016044>] (handle_IPI) from [<c000948c>] (gic_handle_irq+0x64/0x6c) r10:c06ea5a0 r9:c06ea5a0 r8:c04b7e2c r7:ee935f9c r6:c06eb2bc r5:ee935f68 r4:f0002100 [<c0009428>] (gic_handle_irq) from [<c00146c4>] (__irq_svc+0x44/0x7c) Exception stack(0xee935f68 to 0xee935fb0) 5f60: 00000000 00000000 00000000 c06eace8 ee934000 00000015 5f80: c06ce344 ee935fc0 c04b7e2c c06ea5a0 c06ea5a0 ee935fbc ee935fb0 ee935fb0 5fa0: c00107f4 c00107f8 60000113 ffffffff r6:ffffffff r5:60000113 r4:c00107f8 r3:c00107f4 [<c00107b8>] (arch_cpu_idle) from [<c005cc44>] (cpu_startup_entry+0x25c/0x2bc) [<c005c9e8>] (cpu_startup_entry) from [<c0015d10>] (secondary_start_kernel+0x150/0x174) r7:c074403c [<c0015bc0>] (secondary_start_kernel) from [<1000952c>] (0x1000952c) r4:3e91806a r3:c0009514 Internal error: Oops: 17 [#1] PREEMPT SMP ARM Modules linked in: usb_storage(O) ehci_hcd(O) usbcore(O) usb_common(O) CPU: 0 PID: 25 Comm: kworker/0:1 Tainted: G O 4.1.10+ #4 Hardware name: Platform-Cortex A9 Workqueue: pm pm_runtime_work task: eeb10c00 ti: ee0e0000 task.ti: ee0e0000 PC is at ehci_handle_start_intr_unlinks+0x48/0x8c [ehci_hcd] LR is at ehci_bus_suspend+0x388/0x464 [ehci_hcd] pc : [<bf04ec34>] lr : [<bf04ffb0>] psr: 60000193 sp : ee0e1ca8 ip : ee0e1cc8 fp : ee0e1cc4 r10: ffffffff r9 : 00000001 r8 : 00500000 r7 : 00000000 r6 : 00000001 r5 : ede81584 r4 : ede81480 r3 : 00000000 r2 : 00000000 r1 : ffffffe0 r0 : ede81480 Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 3df4404a DAC: 00000015 Process kworker/0:1 (pid: 25, stack limit = 0xee0e0210) Stack: (0xee0e1ca8 to 0xee0e2000) 1ca0: ede81550 ede81300 ede81480 ede8152c ee0e1d14 ee0e1cc8 1cc0: bf04ffb0 bf04ebf8 ee0e1d04 ee0e1cd8 bf00fd0c c005c340 edd8e680 ede81608 1ce0: 00000000 f023e030 00000002 ede81300 ede82f80 00000007 bf024928 00000001 1d00: edd8e940 00000400 ee0e1d4c ee0e1d18 bf00f2c8 bf04fc34 ee0e1d5c ee0e1d28 1d20: bf008d00 bf008a74 ee0e1d54 ede82f80 ffffffff 00000007 00000001 00000402 1d40: ee0e1d5c ee0e1d50 bf01ba0c bf00f204 ee0e1d8c ee0e1d60 bf013730 bf01b9f4 1d60: 00000001 00000000 ede82fe8 ede82f80 60000113 00000000 00000008 00000003 1d80: ee0e1dac ee0e1d90 bf0145fc bf013634 00000000 ede83058 ede82fe8 bf0145c4 1da0: ee0e1dcc ee0e1db0 c02c3e98 bf0145d0 00000004 ede82fe8 00000008 00000000 1dc0: ee0e1de4 ee0e1dd0 c02c3f38 c02c3e60 ede82fe8 00000008 ee0e1e34 ee0e1de8 1de0: c02c4560 c02c3ecc 00000002 ee0e1e00 00000000 c04b4c48 60000113 ede83058 1e00: 00000008 00000002 eedd7400 ede82fe8 ede83058 00000008 60000113 eedd7400 1e20: 00000000 00000000 ee0e1e54 ee0e1e38 c02c559c c02c42e0 ede82fe8 ede82fe8 1e40: bf014660 00000002 ee0e1e6c ee0e1e58 bf014694 c02c5568 00000000 ede83058 1e60: ee0e1e8c ee0e1e70 c02c3e98 bf01466c bf01d80c ede82fe8 00000000 eedd3240 1e80: ee0e1eb4 ee0e1e90 c02c4974 c02c3e60 00000000 ede830b4 ede83058 eedd3240 1ea0: c06e6100 eedd7400 ee0e1ecc ee0e1eb8 c02c56d4 c02c4838 ee0aa500 ede830b4 1ec0: ee0e1f0c ee0e1ed0 c003be98 c02c5670 eedd3240 eedd3240 eedd3240 c06e6100 1ee0: eedd3260 ee0aa500 eedd3240 eedd3240 c06e6100 eedd3260 ee0aa518 00000000 1f00: ee0e1f44 ee0e1f10 c003c95c c003bc54 ee0aa500 c003c68c 00000000 ee0bcc00 1f20: 00000000 ee0aa500 c003c68c 00000000 00000000 00000000 ee0e1fac ee0e1f48 1f40: c00412b0 c003c698 c001257c 00000000 00000000 ee0aa500 00000000 00000000 1f60: dead4ead ffffffff ffffffff ee0e1f6c ee0e1f6c 00000000 00000000 dead4ead 1f80: ffffffff ffffffff ee0e1f88 ee0e1f88 ee0bcc00 c00411b8 00000000 00000000 1fa0: 00000000 ee0e1fb0 c000fcd8 c00411c4 00000000 00000000 00000000 00000000 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff Backtrace: [<bf04ebec>] (ehci_handle_start_intr_unlinks [ehci_hcd]) from [<bf04ffb0>] (ehci_bus_suspend+0x388/0x464 [ehci_hcd]) r6:ede8152c r5:ede81480 r4:ede81300 r3:ede81550 [<bf04fc28>] (ehci_bus_suspend [ehci_hcd]) from [<bf00f2c8>] (hcd_bus_suspend+0xd0/0x1dc [usbcore]) r10:00000400 r9:edd8e940 r8:00000001 r7:bf024928 r6:00000007 r5:ede82f80 r4:ede81300 [<bf00f1f8>] (hcd_bus_suspend [usbcore]) from [<bf01ba0c>] (generic_suspend+0x24/0x44 [usbcore]) r8:00000402 r7:00000001 r6:00000007 r5:ffffffff r4:ede82f80 [<bf01b9e8>] (generic_suspend [usbcore]) from [<bf013730>] (usb_suspend_both+0x108/0x1a8 [usbcore]) [<bf013628>] (usb_suspend_both [usbcore]) from [<bf0145fc>] (usb_runtime_suspend+0x38/0x78 [usbcore]) r10:00000003 r9:00000008 r8:00000000 r7:60000113 r6:ede82f80 r5:ede82fe8 r4:00000000 r3:00000001 [<bf0145c4>] (usb_runtime_suspend [usbcore]) from [<c02c3e98>] (__rpm_callback+0x44/0x6c) r6:bf0145c4 r5:ede82fe8 r4:ede83058 r3:00000000 [<c02c3e54>] (__rpm_callback) from [<c02c3f38>] (rpm_callback+0x78/0x90) r6:00000000 r5:00000008 r4:ede82fe8 r3:00000004 [<c02c3ec0>] (rpm_callback) from [<c02c4560>] (rpm_suspend+0x28c/0x4a8) r5:00000008 r4:ede82fe8 [<c02c42d4>] (rpm_suspend) from [<c02c559c>] (__pm_runtime_suspend+0x40/0x8c) r10:00000000 r9:00000000 r8:eedd7400 r7:60000113 r6:00000008 r5:ede83058 r4:ede82fe8 [<c02c555c>] (__pm_runtime_suspend) from [<bf014694>] (usb_runtime_idle+0x34/0x3c [usbcore]) r7:00000002 r6:bf014660 r5:ede82fe8 r4:ede82fe8 [<bf014660>] (usb_runtime_idle [usbcore]) from [<c02c3e98>] (__rpm_callback+0x44/0x6c) r4:ede83058 r3:00000000 [<c02c3e54>] (__rpm_callback) from [<c02c4974>] (rpm_idle+0x148/0x2ec) r6:eedd3240 r5:00000000 r4:ede82fe8 r3:bf01d80c [<c02c482c>] (rpm_idle) from [<c02c56d4>] (pm_runtime_work+0x70/0x9c) r8:eedd7400 r7:c06e6100 r6:eedd3240 r5:ede83058 r4:ede830b4 r3:00000000 [<c02c5664>] (pm_runtime_work) from [<c003be98>] (process_one_work+0x250/0x428) r5:ede830b4 r4:ee0aa500 [<c003bc48>] (process_one_work) from [<c003c95c>] (worker_thread+0x2d0/0x424) r10:00000000 r9:ee0aa518 r8:eedd3260 r7:c06e6100 r6:eedd3240 r5:eedd3240 r4:ee0aa500 [<c003c68c>] (worker_thread) from [<c00412b0>] (kthread+0xf8/0x10c) r10:00000000 r9:00000000 r8:00000000 r7:c003c68c r6:ee0aa500 r5:00000000 r4:ee0bcc00 [<c00411b8>] (kthread) from [<c000fcd8>] (ret_from_fork+0x14/0x3c) r7:00000000 r6:00000000 r5:c00411b8 r4:ee0bcc00 Code: e5930028 e5942114 e1500002 0a000008 (e8930005)
